Silver halide color photographic materials generally comprise a support having provided thereon at least three silver halide emulsion layers, each of which is selectively sensitized so as to be sensitive to one of blue light, green light, and red light, respectively. For example, so-called color papers usually comprise a support having coated thereon a blue-sensitive emulsion layer, a green-sensitive emulsion layer, and a red-sensitive emulsion layer in this order, with auxiliary layers, e.g., intermediate layers, protective layers, etc., being further provided, for example, between light-sensitive layers for prevention of color mixing, ultraviolet absorption, or the like purpose.
In these color photographic materials, a color image is formed by exposing the material containing yellow, magnta, and cyan couplers in the respective light-sensitive layer and subjecting the exposed material to color development processing with an aromatic primary amine developing agent. By the color development processing, a coupling reaction takes place between an oxidation product of the developing agent and each of the couplers to develop the respective color. It is desired that the couplers to be used have a coupling rate as high as possible and exhibit satisfactory color developability so as to provide high color densities within a limited development time. It is also demanded that the developed colors be distinct cyan, magenta, and yellow colors with reduced side absorptions so as to provide a color photographic image exhibiting satisfactory color reproducibility.
Further, the color photographic image formed is required to have satisfactory preservability under various conditions. In order to meet this requirement, it is important that the developed colors of different hues are retarded from discoloration or color change and that the rates of discoloration are uniform as possible over the entire image area so that the color balance of the remaining color image may not be destroyed.
In an attempt to solve these problems, so-called oil-soluble couplers have been proposed, which are incorporated into emulsion layers by dissolving in high-boiling or low-boiling organic solvents and emulsifying the solution. Use of the oil-soluble couplers is associated with a disadvantage that a color developing agent, because of its low lipophilic properties, hardly penetrates into oil droplets having dispersed therein the coupler, resulting in reduction of color density. Hence, various development accelerators which accelerate penetration of a developing agent into the oil droplets have hitherto been developed. Of these, benzyl alcohol produces a great effect to accelerate color development when added to a color developing solution and is currently employed widely for processing of color photographic light-sensitive materials, in particular color papers.
Use of benzyl alcohol in a color developing solution needs solvents therefor, such as diethylene glycol, triethylene glycol, alkanolamines, etc., due to its poor water solubility. However, since these solvents as well as benzyl alcohol per se have a high BOD or COD indicative of a pollution load, it is preferred to reduce the pollution load by eliminting benzyl alcohol.
Besides, it takes time to dissolve benzyl alcohol even with the aid of the solvent. Therefore, in view of reduction of time and labor involved for the preparation of a color developing solution, exclusion of benzyl alcohol is desirable.
Further, if benzyl alcohol is carried with light-sensitive materials into a bleaching bath or a bleach-fixing bath subsequent to the developing bath, the carried-over benzyl alcohol not only causes formation of a leuco dye from a cyan coupler, which leads to reduction in color density, but also retards removal of developer components by washing, sometimes giving adverse influences on image preservability of the processed light-sensitive materials. From all these considerations, it is preferable to use no benzyl alcohol.
On the other hand, while color development has conventionally been completed within 3 to 4 minutes, it has been demanded to shorten the processing time to cope with the recent users' need or rationalization in photofinishing laboratories. However, it is apparent that removal of benzyl alcohol as a development accelerator, combined with reduction of development time would bring about serious reduction of color density.
In order to solve this problem, efforts have been made by using a combination of various known color development accelerators, such as those disclosed in U.S. Pat. Nos. 2,950,970, 2,515,147, 2,496,903, 2,304,925, 4,038,075, and 4,119,642, British Patents 1,430,998 and 1,455,413, Japanese Patent Application (OPI) Nos. 15831/78, 62450/80, 62451/80, 62452/80, 62453/80, 50536/83, and 162256/85 (the term "OPI" as used herein means "unexamined published application"), and Japanese Patent Publication Nos. 12422/76 and 49728/80. None of these efforts, however, succeeded to attain sufficient color densities.
Methods of incorporating a color developing agent into color photographic light-sensitive materials are known, as described, e.g., in U.S. Pat. Nos. 3,719,492, 3,342,559, and 3,342,597, and Japanese Patent Application (OPI) Nos. 6235/81, 16133/81, 97531/82, and 83565/82. However, these methods are not suitable as causing retardation of color development of fog formation.
Methods of using a silver chloride emulsion, as disclosed in Japanese Patent Application (OPI) Nos. 95345/83, 232342/84, and 19140/85, are also unsuitable because gradation control is difficult.
Various methods for not adding at all benzyl alcohol to a color developing solution or greatly reducing the amount of benzyl alcohol to be added to a color developing solution have been proposed. For example, Japanese Patent Application (OPI) Nos. 200037/82, 50536/83, 487555/84, 174836/84, 177553/84, 162256/85, 158444/85, 158446/85, 26338/85, 26339/85, 172042/85, and 31334/83 and Japanese Patent Publication No. 29461/74 disclose that a multi-layer color light-sensitive material comprising a reflective support having provided thereon blue-sensitive, green-sensitive and red-sensitive silver halide emulsion layers having a yellow coupler, a magenta coupler, and a cyan coupler, respectively is processed with a color developing solution containing no benzyl alcohol or a small amount of benzyl alcohol. However, these prior art references merely describe that when processed with a color developing solution, the light-sensitive material must be processed for a developing time longer than two minutes and a half or that when processed within two minutes and a half, the light-sensitive material must be processed with a color developing solution containing a certain amount of benzyl alcohol.
As set forth above, there has not been established a method of obtaining a satisfactory color image in a short time of not more than two minutes and a half by using a color developing solution at a pH of 12 or less, which contains substantially no benzyl alcohol.